OpenBSD-4.6/usr.sbin/rwhod/rwhod.c
/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1983, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
/*static char sccsid[] = "@(#)rwhod.c 8.1 (Berkeley) 6/6/93";*/
static char rcsid[] = "$OpenBSD: rwhod.c,v 1.32 2009/06/26 09:44:55 claudio Exp $";
#endif /* not lint */
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <netinet/in.h>
#include <protocols/rwhod.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <netdb.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <utmp.h>
#include <err.h>
/*
* Alarm interval. Don't forget to change the down time check in ruptime
* if this is changed.
*/
#define AL_INTERVAL (3 * 60)
char myname[MAXHOSTNAMELEN];
int debug;
/*
* We communicate with each neighbor in a list constructed at the time we're
* started up. Neighbors are currently directly connected via a hardware
* interface.
*/
struct neighbor {
struct neighbor *n_next;
char *n_name; /* interface name */
struct sockaddr *n_addr; /* who to send to */
int n_addrlen; /* size of address */
int n_flags; /* should forward?, interface flags */
};
struct neighbor *neighbors;
struct whod mywd;
struct servent *sp;
int s, utmpf;
volatile sig_atomic_t gothup;
#define WHDRSIZE (sizeof(mywd) - sizeof(mywd.wd_we))
int configure(void);
void getboottime(void);
void hup(int);
void timer(void);
void quit(char *);
void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
int verify(char *);
void handleread(int s);
int Sendto(int, const void *, size_t, int, const struct sockaddr *,
socklen_t);
char *interval(int, char *);
/* ARGSUSED */
void
hup(int signo)
{
gothup = 1;
}
void
usage(void)
{
extern char *__progname;
fprintf(stderr, "usage: %s [-d]\n", __progname);
exit(1);
}
int
main(int argc, char *argv[])
{
struct timeval start, next, delta, now;
struct sockaddr_in sin;
struct pollfd pfd[1];
int on = 1, ch;
char *cp;
while ((ch = getopt(argc, argv, "d")) != -1) {
switch (ch) {
case 'd':
debug = 1;
break;
default:
usage();
}
}
if (getuid())
errx(1, "not super user");
sp = getservbyname("who", "udp");
if (sp == NULL)
errx(1, "udp/who: unknown service");
if (chdir(_PATH_RWHODIR) < 0)
err(1, "%s", _PATH_RWHODIR);
if (!debug)
daemon(1, 0);
(void) signal(SIGHUP, hup);
openlog("rwhod", LOG_PID, LOG_DAEMON);
/*
* Establish host name as returned by system.
*/
if (gethostname(myname, sizeof(myname)) < 0) {
syslog(LOG_ERR, "gethostname: %m");
exit(1);
}
if ((cp = strchr(myname, '.')) != NULL)
*cp = '\0';
strncpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname) - 1);
mywd.wd_hostname[sizeof(mywd.wd_hostname) - 1] = '\0';
utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
if (utmpf < 0) {
syslog(LOG_ERR, "%s: %m", _PATH_UTMP);
exit(1);
}
getboottime();
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
syslog(LOG_ERR, "socket: %m");
exit(1);
}
if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) {
syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
exit(1);
}
memset(&sin, 0, sizeof(sin));
sin.sin_addr.s_addr = INADDR_ANY;
sin.sin_family = AF_INET;
sin.sin_port = sp->s_port;
if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
syslog(LOG_ERR, "bind: %m");
exit(1);
}
if (!configure())
exit(1);
timer();
gettimeofday(&start, NULL);
delta.tv_sec = AL_INTERVAL;
delta.tv_usec = 0;
timeradd(&start, &delta, &next);
pfd[0].fd = s;
pfd[0].events = POLLIN;
for (;;) {
int n;
n = poll(pfd, 1, 1000);
if (n == 1)
handleread(s);
if (gothup) {
gothup = 0;
getboottime();
}
gettimeofday(&now, NULL);
if (timercmp(&now, &next, >)) {
timer();
timeradd(&now, &delta, &next);
}
}
}
void
handleread(int s)
{
struct sockaddr_in from;
struct stat st;
char path[64];
struct whod wd;
int cc, whod;
socklen_t len = sizeof(from);
cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0,
(struct sockaddr *)&from, &len);
if (cc <= 0) {
if (cc < 0 && errno != EINTR)
syslog(LOG_WARNING, "recv: %m");
return;
}
if (from.sin_port != sp->s_port) {
syslog(LOG_WARNING, "%d: bad source port from %s",
ntohs(from.sin_port), inet_ntoa(from.sin_addr));
return;
}
if (cc < WHDRSIZE) {
syslog(LOG_WARNING, "short packet from %s",
inet_ntoa(from.sin_addr));
return;
}
if (wd.wd_vers != WHODVERSION)
return;
if (wd.wd_type != WHODTYPE_STATUS)
return;
wd.wd_hostname[sizeof(wd.wd_hostname)-1] = '\0';
if (!verify(wd.wd_hostname)) {
syslog(LOG_WARNING, "malformed host name from %s",
inet_ntoa(from.sin_addr));
return;
}
if (debug)
printf("host %s\n", wd.wd_hostname);
(void) snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
/*
* Rather than truncating and growing the file each time,
* use ftruncate if size is less than previous size.
*/
whod = open(path, O_WRONLY | O_CREAT, 0644);
if (whod < 0) {
syslog(LOG_WARNING, "%s: %m", path);
return;
}
#if ENDIAN != BIG_ENDIAN
{
int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
struct whoent *we;
/* undo header byte swapping before writing to file */
wd.wd_sendtime = ntohl(wd.wd_sendtime);
for (i = 0; i < 3; i++)
wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
wd.wd_boottime = ntohl(wd.wd_boottime);
we = wd.wd_we;
for (i = 0; i < n; i++) {
we->we_idle = ntohl(we->we_idle);
we->we_utmp.out_time =
ntohl(we->we_utmp.out_time);
we++;
}
}
#endif
(void) time((time_t *)&wd.wd_recvtime);
(void) write(whod, (char *)&wd, cc);
if (fstat(whod, &st) < 0 || st.st_size > cc)
ftruncate(whod, (off_t)cc);
(void) close(whod);
}
/*
* Check out host name for unprintables
* and other funnies before allowing a file
* to be created. Sorry, but blanks aren't allowed.
*/
int
verify(char *p)
{
char c;
/*
* Many people do not obey RFC 822 and 1035. The valid
* characters are a-z, A-Z, 0-9, '-' and . But the others
* tested for below can happen, and we must be more permissive
* than the resolver until those idiots clean up their act.
*/
if (*p == '.' || *p == '-')
return 0;
while ((c = *p++)) {
if (('a' <= c && c <= 'z') ||
('A' <= c && c <= 'Z') ||
('0' <= c && c <= '9'))
continue;
if (c == '.' && *p == '.')
return 0;
if (c == '.' || c == '-')
continue;
return 0;
}
return 1;
}
int utmptime;
int utmpent;
int utmpsize = 0;
struct utmp *utmp;
int alarmcount;
void
timer(void)
{
struct neighbor *np;
struct whoent *we = mywd.wd_we, *wlast;
int i;
struct stat stb;
double avenrun[3];
time_t now;
struct utmp *nutmp;
int cc;
now = time(NULL);
if (alarmcount % 10 == 0)
getboottime();
alarmcount++;
(void) fstat(utmpf, &stb);
/* implicitly safe truncation */
if (stb.st_size > 1024*1024 * sizeof(struct utmp))
stb.st_size = 1024*1024 * sizeof(struct utmp);
if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
utmptime = stb.st_mtime;
if (stb.st_size > utmpsize) {
int nutmpsize = stb.st_size + 10 * sizeof(struct utmp);
nutmp = (struct utmp *)realloc(utmp, nutmpsize);
if (!nutmp) {
warnx("malloc failed");
free(utmp);
utmpsize = 0;
return;
}
utmp = nutmp;
utmpsize = nutmpsize;
}
(void) lseek(utmpf, (off_t)0, SEEK_SET);
cc = read(utmpf, (char *)utmp, (size_t)stb.st_size);
if (cc < 0) {
warnx("%s", _PATH_UTMP);
return;
}
wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
utmpent = cc / sizeof(struct utmp);
for (i = 0; i < utmpent; i++)
if (utmp[i].ut_name[0]) {
memcpy(we->we_utmp.out_line, utmp[i].ut_line,
sizeof(utmp[i].ut_line));
memcpy(we->we_utmp.out_name, utmp[i].ut_name,
sizeof(utmp[i].ut_name));
we->we_utmp.out_time = htonl(utmp[i].ut_time);
if (we >= wlast)
break;
we++;
}
utmpent = we - mywd.wd_we;
}
/*
* The test on utmpent looks silly---after all, if no one is
* logged on, why worry about efficiency?---but is useful on
* (e.g.) compute servers.
*/
if (utmpent && chdir(_PATH_DEV)) {
syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
exit(1);
}
we = mywd.wd_we;
for (i = 0; i < utmpent; i++) {
if (stat(we->we_utmp.out_line, &stb) >= 0)
we->we_idle = htonl(now - stb.st_atime);
we++;
}
(void)getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
for (i = 0; i < 3; i++)
mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
cc = (char *)we - (char *)&mywd;
mywd.wd_sendtime = htonl(time(0));
mywd.wd_vers = WHODVERSION;
mywd.wd_type = WHODTYPE_STATUS;
for (np = neighbors; np != NULL; np = np->n_next)
(void)Sendto(s, &mywd, cc, 0, np->n_addr, np->n_addrlen);
if (utmpent && chdir(_PATH_RWHODIR)) {
syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
exit(1);
}
}
void
getboottime(void)
{
int mib[2];
size_t size;
struct timeval tm;
mib[0] = CTL_KERN;
mib[1] = KERN_BOOTTIME;
size = sizeof(tm);
if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) {
syslog(LOG_ERR, "cannot get boottime: %m");
exit(1);
}
mywd.wd_boottime = htonl(tm.tv_sec);
}
void
quit(char *msg)
{
syslog(LOG_ERR, "%s", msg);
exit(1);
}
#define ROUNDUP(a) \
((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
void
rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
{
struct sockaddr *sa;
int i;
memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
if ((rtinfo->rti_addrs & (1 << i)) == 0)
continue;
rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
ADVANCE(cp, sa);
}
}
/*
* Figure out device configuration and select
* networks which deserve status information.
*/
int
configure(void)
{
struct neighbor *np;
struct if_msghdr *ifm;
struct ifa_msghdr *ifam;
struct sockaddr_dl *sdl;
size_t needed;
int mib[6], flags = 0, len;
char *buf, *lim, *next;
struct rt_addrinfo info;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = AF_INET;
mib[4] = NET_RT_IFLIST;
mib[5] = 0;
if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
quit("route-sysctl-estimate");
if ((buf = malloc(needed)) == NULL)
quit("malloc");
if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
quit("actual retrieval of interface table");
lim = buf + needed;
sdl = NULL; /* XXX just to keep gcc -Wall happy */
for (next = buf; next < lim; next += ifm->ifm_msglen) {
ifm = (struct if_msghdr *)next;
if (ifm->ifm_version != RTM_VERSION)
continue;
if (ifm->ifm_type == RTM_IFINFO) {
sdl = (struct sockaddr_dl *)(ifm + 1);
flags = ifm->ifm_flags;
continue;
}
if ((flags & IFF_UP) == 0 ||
(flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)
continue;
if (ifm->ifm_type != RTM_NEWADDR)
quit("out of sync parsing NET_RT_IFLIST");
ifam = (struct ifa_msghdr *)ifm;
info.rti_addrs = ifam->ifam_addrs;
rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
&info);
/* gag, wish we could get rid of Internet dependencies */
#define dstaddr info.rti_info[RTAX_BRD]
#define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
#define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
continue;
PORT_SA(dstaddr) = sp->s_port;
for (np = neighbors; np != NULL; np = np->n_next)
if (memcmp(sdl->sdl_data, np->n_name,
sdl->sdl_nlen) == 0 &&
IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
break;
if (np != NULL)
continue;
len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
np = (struct neighbor *)malloc(len);
if (np == NULL)
quit("malloc of neighbor structure");
memset(np, 0, len);
np->n_flags = flags;
np->n_addr = (struct sockaddr *)(np + 1);
np->n_addrlen = dstaddr->sa_len;
np->n_name = np->n_addrlen + (char *)np->n_addr;
np->n_next = neighbors;
neighbors = np;
memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
}
free(buf);
return (1);
}
int
Sendto(int s, const void *buf, size_t cc, int flags,
const struct sockaddr *to, socklen_t tolen)
{
struct whod *w = (struct whod *)buf;
struct whoent *we;
struct sockaddr_in *sin = (struct sockaddr_in *)to;
int ret;
ret = sendto(s, buf, cc, flags, to, tolen);
if (debug) {
printf("sendto %s.%d\n", inet_ntoa(sin->sin_addr),
ntohs(sin->sin_port));
printf("hostname %s %s\n", w->wd_hostname,
interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime),
" up"));
printf("load %4.2f, %4.2f, %4.2f\n",
ntohl(w->wd_loadav[0]) / 100.0,
ntohl(w->wd_loadav[1]) / 100.0,
ntohl(w->wd_loadav[2]) / 100.0);
cc -= WHDRSIZE;
for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0;
cc--, we++) {
time_t t = ntohl(we->we_utmp.out_time);
printf("%-8.8s %s:%s %.12s",
we->we_utmp.out_name,
w->wd_hostname, we->we_utmp.out_line,
ctime(&t)+4);
we->we_idle = ntohl(we->we_idle) / 60;
if (we->we_idle) {
if (we->we_idle >= 100*60)
we->we_idle = 100*60 - 1;
if (we->we_idle >= 60)
printf(" %2d", we->we_idle / 60);
else
printf(" ");
printf(":%02u", we->we_idle % 60);
}
printf("\n");
}
}
return (ret);
}
char *
interval(int time, char *updown)
{
static char resbuf[32];
int days, hours, minutes;
if (time < 0 || time > 3*30*24*60*60) {
(void) snprintf(resbuf, sizeof(resbuf),
" %s ??:??", updown);
return (resbuf);
}
minutes = (time + 59) / 60; /* round to minutes */
hours = minutes / 60; minutes %= 60;
days = hours / 24; hours %= 24;
if (days)
(void) snprintf(resbuf, sizeof(resbuf),
"%s %2d+%02d:%02d", updown, days, hours, minutes);
else
(void) snprintf(resbuf, sizeof(resbuf),
"%s %2d:%02d", updown, hours, minutes);
return (resbuf);
}